Development of a Fully Autonomous Micro Aerial Vehicle for Ground Traffic Surveillance

Aerospace Systems, University of Braunschweig

Contents  Introduction  Theoretical Work  The Hardware of “Carolo”  Applications  Current Status & Outlook Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003 2

Introduction - What is an MAV ?

   

definition according to DARPA semiautonomous aerial vehicle max. dimensions: 15 x 15 x 15 cm max. mass: ~ 115 g (4 ounces) cost: < 1000$ additional requirements

    

telemetry link to ground control (for remote control) real-time video link range: ~ 10 km cruising speed: ~ 50 km/h endurance: 20 min - 60 min

Aerospace Systems, University of Braunschweig Black Widow, Aerovironment Inc.

Entomopter, GeorgiaTec Journées Micro-Drones 2003 3

Introduction - The Project “Carolo” Goal: development of an autonomously operating Micro Aerial Vehicle with dimensions as small as possible wing span mass cruising speed endurance range 0.40

m

390

g

18

m / s

40

min

45

km

4 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Theoretical Work 5 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Theoretical Work – Overall Control Structure wind pilot, navigation module autopilot attitude controller actuators sensors damper 6

modeling of



non-linear flight mechanics



turbulent atmosphere



sensor dynamics



actuator dynamics

Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Theoretical Work - Database Wind Tunnel Readings 5 - dimensional parameter field

C X , C Y , C Z , C L , C M , C N = f(

a, b, h, x, k

)

Angle of Attack Sideslip Elevator Aileron Flaps -10 -32 -15 ° -15 -8 ° ° ° ° < < < < < a b h x k < 40 ° < 32 < 15 < 15 < 12 ° ° ° ° Wind tunel test april 2002 at the Institute of Fluid Dynamics, Technical University of Braunschweig Aerospace Systems, University of Braunschweig Calculated Damping Derivatives Roll Damping Pitch Damping Yaw Damping C Lp C Mq C Nr Journées Micro-Drones 2003 7

Theoretical Work - Results

Simulation of the autopilot 8 simulation with:  actuator dynamics  sensor error models  carolo‘s control algorithms  stable behavior, stationary accuracy  oscillations due to sensor deadtime, GPS update rate missing curved flight compensation Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

The Hardware of “Carolo” 9 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

The Hardware of “Carolo” - Anatomy telemetry on-board computer payload 10 sensors propulsion system actuators Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

The Hardware of “Carolo” - Sensors 

receiver for Global Positioning System (GPS)



atmospheric pressure sensor



Inertial Measurement Unit (IMU)



Micro-Electro-Mechanical Systems



3 angular rate sensors



3 linear acceleration sensors



commercial-off-the-shelf components (COTS)



in-flight sensor data fusion

Aerospace Systems, University of Braunschweig MEMS-based 6-dof IMU Journées Micro-Drones 2003 11

The Hardware of “Carolo” - Sensor Calibration 12 comparison of MAV IMU data with Honeywell LaserNav, test flight with the university‘s research aircraft DO128 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

The Hardware of “Carolo” - Onboard Electronics GPRS 13

current autopilot hardware

dimensions: 75mm*40mm*38 mm mass: 85 gr.

including: on-board computer gps & antenna 3 accelerometers 3 gyros 3-axis magnetometer 2 pressure sensors

video camera:

25 gr. (analog)

telemetry:

50 gr. (future) Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Applications The MAV “Carolo”, wingspan 40 cm, mass 390 g Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003 14

Applications

possible applications



meteorology

–

vertical profiles of temperature and humidity

–

increase of spatial resolution by using multiple MAVs



Live video transmission

–

Police, border patrol, military applications

–

Civil protection

–

Ground traffic surveilance

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Ground Traffic Surveillance - Concept

Carolo mission control

16

GPRS / UMTS mobile access of information

Aerospace Systems, University of Braunschweig    

data analysis police, fire department ambulance accident investigation highway board department

Journées Micro-Drones 2003

Ground Traffic Surveillance - Image Sensor 

current: analog video camera

– – – –

mass: ~ 25 g dedicated radio downlink live video stream short range: ~ 200 m



under progress: digital CMOS camera

– – – – –

mass: ~ 30 g resolution: 1.3 megapixel image transmission via telemetry link frame rate depends on telemetry data rate on-board image compression possible

Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003 17

Ground Traffic Surveillance - Telemetry 

mobile cellular phone network

– – –

infrastructure already available virtually unlimited range comparably low data rate requires image compression (e.g. JPEG2000) type data rate GSM GPRS UMTS 9.6 kbps 28.8 kbps 384 kbps

comparison of different standards for mobile communication Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003 18

Ground Traffic Surveillance - Aerial Image Quality 

no compression



field of view: 510 m x 380 m



image size: 1024 x 768 pixel



data size: 2304 kbyte

19 high-resolution aerial picture, no compression Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Ground Traffic Surveillance - Aerial Image Quality 

JPEG2000 (rate 1:40)



field of view: 510 m x 380 m



image size: 1024 x 768 pixel



data size: 60 kbyte

20 high-resolution aerial picture, compression rate 1:40 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Ground Traffic Surveillance - Aerial Image Quality 

JPEG2000 (rate: 1:40)



field of view: 160 m x 120 m



image size: 320 x 240 pixel



data size: 5.5 kbyte

21 low-resolution aerial picture, compression rate 1:40 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Ground Traffic Surveillance - Telemetry

type GSM GPRS UMTS data rate 9.6 kbps 28.8 kbps 384 kbps time per hi-res. image 62.5 s 20.8 s 1.6 s time per lo-res. image 5.7 s 1.9 s 0.2 s

comparison of different standards for mobile communication Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003 22

Ground Traffic Surveillance - Ground Control 23 ground control PC software, server-client-based Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Current Status & Outlook

24 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

Current Status - Towards Autonomous Flight Altitude Controller - August 2003 Waypoint Navigation - September 2003 25    circling during strong thermal activity D H < 2m no optimized feedback gains Aerospace Systems, University of Braunschweig  succesful test of complete autopilot  test platform: model plane, span 1.5 m Journées Micro-Drones 2003

Outlook - Field Test 

cooperation with the German automobile club “ADAC Niedersachsen/Sachsen-Anhalt”



agreement with local and federal authorities



scheduled for Spring 2004

26 “Carolo XL”, wingspan 100 cm, mass 940 g Aerospace Systems, University of Braunschweig MAV “Carolo”, wingspan 40 cm, mass 390 g Journées Micro-Drones 2003

Carolo‘s Flight, December 2002

27 Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003

1

st

autonomous Flight, September 5th, 2003

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First European Micro Air Vehicle Conference and Flight Competition

EMAV 2004

Braunschweig, Germany 13 – 14 Juli 2004 organised by the German Institute of Navigation

Aerospace Systems, University of Braunschweig Journées Micro-Drones 2003 29